1. Field of Invention
This invention relates generally to flashlights, and more particularly to a flashlight provided with a switch assembly that when momentarily actuated by an operator functions to connect a light bulb to a battery power supply to turn the flashlight "on" for a predetermined interval, at the conclusion of which the flashlight is automatically turned "off."
2. Status of Prior Art
In a conventional flashlight, a manually-operated switch functions to turn the flashlight "on" and "off." When turned "on," battery power is applied through the closed switch to a light bulb, the amount of power then consumed depending on how long the switch is closed.
In the typical flashlight, the effective life of the batteries is only a few hours at most. Should the operator, after using the flashlight to find his way in the dark or for any other purpose, then fail or forget to turn it off, the batteries will in a fairly short time become exhausted. And should the flashlight be left in the turned-on and exhausted condition for a prolonged period, the batteries may then leak and exude a corrosive electrolyte that is damaging to the contacts which engage the battery terminals as well as the casing of the flashlight.
When a flashlight is designed for use by a young child, the likelihood is greater that the flashlight will be mishandled, for a young child is prone to be careless and to forget to turn the flashlight "off" after it has served its purpose. Because of this, a flashlight may be left "on" for days, if not weeks, and as a result of internal corrosion may no longer be in working order when the exhausted batteries are replaced.
Flashlights designed for young children are sometimes in a lantern format, with a casing made of strong plastic material that is virtually unbreakable, the light bulb being mounted within a reflector at the front end of the casing and being covered by a lens from which a light beam is projected. A U-shaped handle is attached to the upper end of the casing, with an on-off slide switch being mounted on the handle, so that a child grasping the handle can readily manipulate the slide actuator with his thumb.
With a switch of this type on top of a flashlight handle, when the slide actuator is pushed forward by the thumb, the flashlight is turned "on" and remains "on" until the slide actuator is pulled back to the "off" position. It is this type of switch in the hands of a child that is most likely to be inadvertently left "on."
To avoid this problem, many flashlights include, in addition to a slide switch, a push button switch which keeps the flashlight turned on only when finger pressure is applied to the push button. It is difficult for a young child who wishes, say, to illuminate a dark corner in the basement of his home for about 30 seconds, to keep a push button depressed for this period. He is therefore more likely to actuate the slide switch to its permanently-on position, for this requires only a momentary finger motion.
A flashlight is essential equipment in children's summer camps. But should the child go on a night hike with fellow campers, he requires not only a flashlight but also a compass to find his way, and a whistle should the child become lost and wish to attract attention. A child is not likely to misplace a flashlight which is relatively bulky. However, this is not true of a small whistle and a compass; hence a need exists to integrate a flashlight with a whistle and compass to avoid the loss of the smaller items.
It is known to provide a flashlight with a delayed action switch which automatically turns off after a predetermined interval. Thus, the Mallory Pat. No. 3,535,282 discloses a flashlight that is automatically turned off by a delayed action switch assembly that includes a compression spring housed in a bellows having a leaky valve, so that when a switch is turned on manually, this action serves to compress the bellows which after a predetermined interval acts to turn off the switch.
A similar delayed action is obtained in a flashlight for children marketed by the Playskool Company, this delayed action being realized by means of a resistance-capacitance timing network which applies a bias to a solid-state transistor switch after 30 seconds or so to cut off the transistor and shut off the flashlight.
In the field of telephones, it is known to obtain a delayed switching action by means of a suction cup. This is disclosed in the Gulnick Pat. No. 2,810,797. In Lehman Pat. No. 3,646,302, a delayed switching action by means of a suction cup is effected in a lamp cord switch.